From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p212wJAq171190 for ; Mon, 28 Feb 2011 20:58:19 -0600 Received: from mail.sandeen.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 45DBE1DDC1A4 for ; Mon, 28 Feb 2011 19:01:06 -0800 (PST) Received: from mail.sandeen.net (sandeen.net [63.231.237.45]) by cuda.sgi.com with ESMTP id ooEJx6KKEf9GfECE for ; Mon, 28 Feb 2011 19:01:06 -0800 (PST) Message-ID: <4D6C6171.8070105@sandeen.net> Date: Mon, 28 Feb 2011 21:01:05 -0600 From: Eric Sandeen MIME-Version: 1.0 Subject: Re: [PATCH] xfs: zero proper structure size for geometry calls References: <4D6C28A5.60905@mnsu.edu> <4D6C4DEE.6020902@sandeen.net> <20110301025944.GG3087@dastard> In-Reply-To: <20110301025944.GG3087@dastard> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: Jeffrey Hundstad , Dan Rosenberg , Eugene Teo , xfs@oss.sgi.com On 2/28/11 8:59 PM, Dave Chinner wrote: > On Mon, Feb 28, 2011 at 07:37:50PM -0600, Eric Sandeen wrote: >> commit 493f3358cb289ccf716c5a14fa5bb52ab75943e5 added: >> >> + memset(geo, 0, sizeof(*geo)); >> >> but unfortunately we're dealing with a cast pointer here, and >> the caller may actually have a smaller structure on the stack. >> Zeroing out more leads to stack corruption traps: >> >> Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: f87aca93 >> >> Pid: 262, comm: xfs_fsr Not tainted 2.6.38-rc6-493f3358cb2+ #1 >> Call Trace: >> >> [] ? panic+0x50/0x150 >> [] ? __stack_chk_fail+0x10/0x18 >> [] ? xfs_ioc_fsgeometry_v1+0x56/0x5d [xfs] >> >> Fix this by zeroing out the structure in the callers, where we know >> the actual size. >> >> Reported-by: Jeffrey Hundstad >> Signed-off-by: Eric Sandeen >> --- >> >> diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c >> index f5e2a19..34e401f 100644 >> --- a/fs/xfs/linux-2.6/xfs_ioctl.c >> +++ b/fs/xfs/linux-2.6/xfs_ioctl.c >> @@ -698,6 +698,7 @@ xfs_ioc_fsgeometry_v1( >> xfs_fsop_geom_v1_t fsgeo; >> int error; >> >> + memset(&fsgeo, 0, sizeof(xfs_fsop_geom_v1_t)); > > I'd prefer that sizeof(fsgeo) is used here. That means if the type > is changed, then memset doesn't need to be. Same for all the rest > of the memset calls. > > Otherwise, > > Reviewed-by: Dave Chinner > > Cheers, > > Dave. Ok, I can resend, I was going to do that but most of xfs uses the other style so wasn't sure. -Eric _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs